Electroresponsive device



Oct. 12 1926. 1,603,060

I v H. w. BROWN 1 ELECTRORESPONSIVE DEVICE Filed March 25. 1926 Inventor: 0 Harold W.Brown.

y MW Hts Attorney.

Patented Oct. 12, 1926.

UNITED STATES PATENT OFFICE.

HAROLD W. BROWN, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRORESPONSIVE DEVICE.

Application filed March 25, 1926. Serial No. 97,447.

My invention relates to improvements in electroresponsire devices such as relays for controlling electric circuits and apparatus in response to predetermined conditions, and has for an object to provide an improved. sensitive and economical electroresponsive device which will operate in accordance with the relative values of a plurality of electric quantities, such as the potentials across a source and across the load supplied thereby, and also on the occurrence of abnormal circuit conditions such as over or under-current, over or iuuler-voltage, reversal of current or voltage, or combinations of these conditions.

My invention will be better understood from the following description, taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

In the accompanying drawing, Fig. 1 is a partly sectional elevation of an actual electroresponsive device embodying my invention, and Fig. 2 is a top plan view of the device shown in Fig. 1.

The illustrated embodiment of my invention is an elcctrm'esponsive device or relay cmuprising a magnetic core 3, energizing wimlings 4 and 5 thereon, an armature 6, and means for controlling the armature in accordance with the ditlerence between two forces which are respectively dependent on the sum of and the difference between the ma netomotive forces of the windings 4 and 5. This controlling means may comprise a magnetic member, such as a pole piece 7, projecting from the core 3 intermediate the windings 4; and 5, and an arrangement of the armature 6 and the ends of the core 3, such that the armature 6 presents a pole face 8 adjacent one end of the core, and a portion 9 between the pole piece 7 andthe other end of the core.

A. particularly compact and economical device can be obtained if the armature 6 is made substantially Lshaped, as shown, and also if the pole piece 7 and a pole piece 10 secureiilto one end of the core 3 have spaced overlapping extensions 11 and 12 respectively, forming an air gap in which the armature portion 9 is movable. The pole pieces 7 and 10 may also be substantially L-shaped, as shown, the extensions 11 and 12 forming outstanding legs between which the armature is n'iovable. The end of the core 3 adjacent the pole face 8 of the armature 6 may be pro vided with an enlarged pole piece 13 to insure a suitable flux and flux density in the gap between the core and the armature pole face. In view of the compact arrangement of the magnetic circuits and the relatively small mass of the magnetic parts, the effect of stray fields, in so far as concerns the proper operation of the relay, is practically eliminated.

The pole piece 10 may be secured to the core 3 by suitable fastening means, such as ascrew 14. The pole piece 7 is held in place between the winding spools and the pole piece 13 is mounted on the end of the core 3. F or maintaining this assembly, a non-magnetic member, such a bracket 15, secured to the end of the core 3 and to the pole piece 10 by suitable fastening means, such as screws 16 and 17 respectively, may be used. Since all the parts, such as the armature 6, the pole pieces 7, 10 and 13 and the bracket may be readily and cheaply formed from flat rolled. or strip material and quickly assembled, a particularly economical construction is obtained.

The armature 6 is pivotally mounted at 18 in a support 19 of non-magnetic material, secured to the bracket 15. In order to avoid the effects of vibration and shock, the armature 6 is preferably pivoted on an axis pass ing through its center of gravity. The armature 6 is biased for counter-clockwise movement by any suitable means, such as a spring 20 and the bias may be varied by a spring plate 21, adjustably positioned on the armature. In order to adjust the gap between the pole piece 7 and the armature 6, suitable adjusting means, such as a screw 22, mounted in the extension 11 of the pole piece 7, may be provided. In order to prevent displacement of the pole piece extensions 11 and 12, nonmagnetic braces 23, secured thereto, may be provided. becured to the armature 6, and suitably insulated therefrom, is a bridging contact 24,, which is arranged when the armature is attracted toward the pole piece 13 to close contacts and 26. These contacts are mounted upon and suitably insulated from the bracket 15, and are provided with suitable terminals 27 and 28 respectively. Vhile the contacts are shown as circuit closing upon clockwise movement of the armature and circuit opening upon counter clockwise movement. contacts may also be provided for the reverse operation or for ieoth operations.

ll ith this construction and arrangement of parts and assuming one or both of the windings t and 5 to be energized, the armature 6 is subjected to the control of four forces. Two of these forces. namely, the attraction between the armature pole face 8 and the pole piece 13, and the attraction between the armature portion 9 and the extension 12 of the pole piece it), tend to turn the armature t3 clockwise. The other two forces, namely, the tension of the spring 20 and the attractive force between the armature portion 9 and the extension 11 of the pole piece 7. tend to turn the armature (3 counter-clockwise. The armature 6 will, therefore take a position dependent on the resultant torque produced by these four forces. This resultant torque as will appear from the following, is dependent on the sum of and the difference between the magnetomotive forces of the windings l and 5.

Assuming, for purposes of explanation. that the windings t and 5 when energized by direct currents tend to establish iuxes in the core 3 in the same direction then, neglecting leakage flux. substantially all of the tlux due to the winding 5 and a part of the fiux due to the winding traverse the gap between the pole piece 13 and the armature pole face 8. Consequently. the attractive force acting' between the pole piece 13 and the armature 6. and tending to turn the armature clockwise, is dependent on the sum of the flux due to the magnetomot-ive force of the winding 5 and a part of the flux due to the magnetomotive force of the winding at, that is fluxes dependent on the relative energizations of the windings. The remainder of the flux due to the winding l tends to traverse the pole piece 7. the extension 11 thereof, the armature portion 9, the pole piece extension'lQ. and the pole piece to the core 3. The flux in the armature 6 due to the winding 5 tends to divide atthe armatnre portion 9, a part going into the pole piece 7 through its polar extension 11 in opposition to the flux therein due to the winding l, and the remainder going into the pole piece 10 through its polar extension 12. The portion of the flux due to the winding 4 traversing the whole of the armature 6 goes into the pole piece 10 through its extension 12. There is. therefore, an attractive force acting between the pole piece 10 and the armature 6 and tending to turn the armature clockwise. This force is dependent on the sum of a part of the flux due to the magnetomotive force of the winding 5, and all of the flux due to the magnetomotive force of the winding that is linxes dependent on the relative energizations of the windings. There is also an ttractive force acting between the pole piece 7 and toe armature 6, and tending to turn the armature counter-clockwise. This force is proportional to the difference between a part of the flux due to the magnetomotive force of the winding i and a part of the flux due to the magnetomotive force of the winding 5. I

In order to prevent clockwise movement of the armature 6, when, for example, one of the windings such as the winding 4 is highly energized the several pole faces and gaps are so proportioned that the resultant torque will not overcome the effect. of the spring 20. The same result can also be ob tained by having a portion of the magnetic circuit such as the pole piece 10, which is primarily associated with the winding at arranged to saturate at a predetermined energization thereof. A combination of both schemes will also serve the purpose.

If the winding t be energized and the winding 5 deenergized, the armature S will take the position shown. If new winding 5 be energized by current at an increasing potential, then. when the potential on the winding 5 attains a predetermined value relative to the potential on the winding 4, the efi'ect of the forces whose resultant is dependent on the sum of the magnetomotive forces of the windings l and 5 will overcome the effectof the force which is dependent on the difference between the magnetomotive forces of the windings and the spring torque. The armature (3, therefore. moves to the contact-closing position where it will remain so long as the resultant or predominating torque is clockwise. Thus, if after the armature closed the contacts, the winding l were deenergized, the armature would relnain in contact-closing position by reason of the n'iagnetomotive force of winding 5, so long as the potential on this winding created at the ends of the armature attractive forces whose resultant when combined with the spring torque gave a clockwise torque. i\s soon as the winding 5 was deenergized, the spring will return the armature to the position shown. It is, therefore, possible with electroresponsive devices embodying my invention to obtain an action based on relative current and/or potential values.

If both of the windings 4 and 5 be as- .sumed to be energized, for example one of the windings, such as the winding 4, in accordance with the potential of a circuit and the other winding 5 in accordance with the current or the potential of the circuit or both in accordance with the current of the circuit. so as to produce fluxes in the same direction in the core 3, then with current or potential in the winding 5 in excess of apredetermined value. the armature (3 would be held in the contact-closing position because the clockwise torque would predomi nate, but if the current or, potential in the winding 5 were reduced below the predetermined value, the differential torque and the spring torque would exceed the cumulative torques, and the armature 6 would assume the position shown. Electroresponsive devices embodying my invention are, therefore, adapted for use as under-power, under-voltage and under-current relays.

If both of the windings 4 and 5 be assumed to be energized, for example, one of the windings such as the win-ding 4 in accordance with the potential of a circuit or of fixed polarity, and the other winding 5 in accordance with the current or potential of the circuit, so as to produce fluxes in opposite directions in the core 3, the armature 6 will be held in the position shown, In this case, the flux in the pole piece 7, that is, the attractive force between the pole piece extension 11 and the armature portion 9 is dependent on the sum of the magnet-oniotive forces of the windings 4 and 5. Upon reversal of the current or potential in the winding 5, the flux in the pole piece 7, that is, the attractive force between the pole piece extension 11 and the armature portion 9 be comes dependent on the difference between the magnetomotive forces of the windings 4 and 5. Consequently, the armature 6 is moved to the circuit-closing position, since the clockwise torque due to the attractive forces between the armature 6 and the pole pieces 10 and 13 exceeds the counter-clockwise torque due to the attractive force between the armature and the pole piece 7 and to the spring 20. Electroresponsive devices embodying my invention are, therefore, adapted for use as voltage directional or current directional relays.

lVhile I have shown and described my invention in considerable detail, I do not desire to be limited to the exact arrangements shown, but seek to cover in the appended claims all those modifications that fall within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is 1. An electroresponsive device comprising a magnetic core, pole pieces projecting from the core at a point intermediate its ends and at one end respectively and having spaced overlapping extensions forming an air gap, windings on the core on opposite sides of the pole piece projecting from said intermediate point, and a pivoted armature presenting a pole face adjacent the other end of the core and a portion movable in the air gap between said extensions.

2. An electroresponsive device comprising a magnetic core, a pole piece projecting from the core intermediate its ends, energizing windings on the core on opposite sides of the pole piece, and an armature constructed and arranged to be attracted by the pole piece in accordance with the difference bctween fluxes dependent on the relative encrgizations of the windings.

3. An electroresponsive device comprising a magnetic core, spaced overlapping pole pieces projecting from the core at a point intermediate its ends and at one end respec tively, windings on the core on opposite sides of the pole piece projecting from said intermediate point, and a pivoted armature presenting a pole face adjacent the other end of the core and a portion between said pole pieces.

4:. A differential electroresponsive device comprising a. magnetic core, two windings thereon, an armature, and means for controlling the armature in accordance with the difference between forces respectively dependent on the sum of and the difference etWeen the magnetomotive forces of the coils comprising pole pieces projecting from the core at one end thereof and from a point intermediate the windings, said armature be ing constructed and arranged to present a pole face adjacent the other end of the core and to have a portion movable between the pole pieces.

5. An electroresponsive device comprising a magnetic core, pole pieces projecting from the core at a point intermediate its ends and at one end respectively, windings on the core on opposite sides of the pole piece projecting from said intermediate point, and an armature constructed and arranged to be attracted by one of said pole pieces in accordance with the difference between fluxes dependent on the relative energizations of the windings and to be attracted by the other pole piece in accordance with the sum of fluxes de pendent on the relative energizations of the windings.

6. An electroresponsive device comprising a straight magnetic core, L-shaped pole pieces mounted on said core at a point intermediate its ends and at one end respectively and having their outstanding legs spaced and overlapping to form an air gap, windings on the core on opposite sides of the pole piece projecting from said intermediate point, and an L-shaped pivotally mounted armature having one leg adjacent the other end of the core and the other leg extending into the air gap between said outstanding legs.

7. An electroresponsive device comprising a magnetic core, an armature, windings on the core, and means for controlling the armature in accordance with the difference between forces respectively dependent on the sum of and the difference between the magnetomotive forces of the coils comprising a magnetic member projecting from the core intermediate the windings.

8. An electroresponsive device comprising a magnetic core, an armature, windings on the core, means for controlling the armature in accordance with the difference between iorces respectively dependent on the sum of and the difference between the inagnetoinotive forces of the coils comprising a magnetic member projecting from the core in termediate the windings and a pole piece projecting from one end of the core and overlapping the magnetic member. W

In Witness whereof I have hereunto set my hand,

HAROLD V. BROWN. 

